Events in worksheets

You can use PI DataLink to create displays for viewing, understanding, and analyzing events stored in PI AF. Your system configuration and the type of data collected determine which events your system stores. For example, your system might have events that store information about batch processes or events created from calculations.

You can use two PI DataLink functions to retrieve events:

• Explore Events function

  Useful for exploring events anywhere in your event hierarchy, the Explore Events function returns one event per row. You can use the Explore Events function to examine the data in a simple hierarchy, such as to analyze the events for a particular element. For example, you might examine the downtime of a particular boiler.

  Exploring events related to an element

  

  You can also use the Explore Events function to examine the events in a full hierarchy, such as to analyze the child events for a type of event. (The event template often indicates the type of event.) For example, you might examine the startup phases of turbines.

  Exploring events with child events

  

• Compare Events function

  Useful for comparing hierarchical events, the Compare Events function can return attributes from related events in a single row. In displays created from the Compare Events function, each row can show a retrieved event along with information from that event's child events and parent events. Including this information can help you compare the retrieved events. For example, including information about a startup event's phase events can help you compare multiple startup events.

  The Compare Events function identifies attributes by path. Therefore, attribute names and hierarchical location affect the display. The capabilities of the function differ depending on the structure of the events and their attributes:

  • Events that have child events with identical names

    If you have a set of events that have identically named child events, then you can compare those events by including child-event information and parent-event information. Specify the criteria to find the events with identically named child events. The Compare Events function can then include information about child events in the same row as each matched event. For example, you might compare turbine-startup events that have identically named phase events, such as Phase1, Phase2, and Phase3.

    Comparing events by including child-event information

    

    The Compare Events function can also include information about parent events in the same row as a matched event. You might include information from the parent event to provide more information about the matched events. For example, for the matched turbine-startup events, information about the parent process event might enhance your comparison.

    Comparing events by including child-event and parent-event information

    

  • Events that have child events with different names

    If you have a set of events that have child events with different names, then you can only compare events by including parent-event information. Specify the criteria to find the lowest-level events in the hierarchy. The Compare Events function can then include information from parent events in the same row as each matched event. For example, suppose you have first-phase events with different names, such as Phase1, P1, PhaseX, and PhaseA. You can compare the phase events and include information about the parent startup event.

    Comparing events by including parent-event information